When you drag down from the top of the screen (intentionally or unintentionally) inside of full-screen apps, a grabber that lets you open Notification Center presents itself. While it works fine for what it was made for, many would agree that it's useless beyond opening Notification Center.
That's where a jailbreak tweak called StatusPeek 2 by Noeliel can come in handy and improve things for the better. It replaces the usual grabber with a sneak peek of your Status Bar while maintaining the function of a grabber.
When installed, pulling down from the top of the display will reveal your Status Bar rather than the little box with a down-facing arrow, and it disappears in exactly the same amount of time as the typical grabber would. On the other hand, you get to see more information at a glance and you can even pull down a second time to launch Notification Center as usual.
With that in mind, you don't have to go through such an intrusive process of covering your whole interface with a blurry blanket just to check your battery or signal level, or to simply glance at the time like you would normally do with the stock grabber.
StatusPeek 2 works best in full-screen games, but it works with other apps as well, such as the Photos app demonstrated above. The tweak operates in both landscape and portrait orientation, which makes it useful for a wide variety of applications.
StatusPeek 2 adds a preferences pane to the Settings app where it can be toggled on or off on demand and a theme can be applied: